Alternative Ways of Providing Water. Emerging Options and Their Policy Implications

Transcription

1 Alternative Ways of Providing Water Emerging Options and Their Policy Implications «ENVIRONMENT Advance copy for 5 th World Water Forum

2 FOREWORD Reused water (either reclaimed water or grey water reuse) is increasingly considered a sustainable source for some uses of water. It is regarded as one option to address the increasing mismatch between available water resources and rising demand, in both OECD and developing countries. Reused water can be supplied from either centralized or decentralized systems. This report reviews the pros and cons of alternative sources of water (reused water and rainwater) and of decentralized systems to collect, produce and use them. It assesses lessons learned and the main policy issues which have to be addressed before such alternative ways of providing water can be widely applied; the focus is on urban areas in OECD countries. The report builds on the analyses developed in the context of the OECD project on Infrastructure to 2030 (OECD, 2007a, b), on a literature review and on a series of discussions with experts. This report is part of the wider OECD Horizontal Water Programme on Sustainable Financing to Ensure Affordable Access to Water Supply and Sanitation. The Programme addresses the economic basis for sustainable water and sanitation services and for sound water resources management. In particular, it addresses two related sets of policy questions of high priority on the international agenda: i) how to overcome the financial obstacles to the provision of adequate, affordable and sustainable water and sanitation services for all, while ensuring revenue sufficiency for service providers, and ii) how to improve the use of economic incentives to encourage management of water resources that is both economically efficient and environmentally sustainable. The main conclusions of the OECD Horizontal Water Programme are synthesized in a synthesis report (OECD, 2009) and in a series of analytical reports (available at The report was written by Xavier Leflaive, Principal Administrator, OECD, Environment Directorate, Environment and Globalisation Division. It has benefited from discussions during the SIWI GWP EUWI Workshop on Progress in Financing Water Services at the Stockholm Water Week (August 2007) and the OECD Expert Meeting Sustainable Financing for Affordable Water Services: From Theory to Practice" (November 2007). The contributions of following experts who have taken time to answer questions and share ideas in the course of this and related projects are gratefully acknowledged: Jeff Ball (Orenco Systems), J. Freedman and James W. Hotchkies (General Electric), Peter Gleick and Meena Palaniappan (Pacific Institute), Hans G. Huber (Huber Technologies), Michel Le Sommer (Le Sommer Environnement), David Lloyd Owen (Envisager), Dominique Lorrain (EHESS), Jack Moss (Aquafed), Peter Shanaghan (USEPA), James Winpenny (Wychwood Consult). The report benefited from comments from the team of the OECD Horizontal Water Programme, under the supervision of Brendan Gillespie, in particular Peter Börkey, Céline Kaufman, Roberto Martin-Hurtado, Monica Scatasta. All errors and inconsistencies remain the author s responsibility. 1

3 TABLE OF CONTENTS FOREWORD... 1 EXECUTIVE SUMMARY... 3 INTRODUCTION... 6 OPPORTUNITIES FOR ALTERNATIVE WATER SYSTEMS... 7 Challenges that prevailing approaches face in OECD countries... 7 Trends in the provision of water supply PROS AND CONS OF ALTERNATIVE WATER SYSTEMS Cost factors for water reuse and decentralized systems Harnessing new sources of finance: capturing some of the rent attached to water services Contextual features POLICY CONCLUSIONS Address public concerns Adjust governance Reform institutions Adjust the regulatory framework Create markets for alternative water systems References Tables Table 1. A typology of ways of providing water and sanitation Table 2. Pros and cons of alternative ways of providing water and sanitation Boxes Box 1. Water Reuse at the Olympics: Beijing Bei Xiao He Box 2. Water reclamation, Hong Kong Box 3. Land value capture and new infrastructure: the Copenhagen metro, Denmark Box 4. Inset appointments in England Box 5. Innovation in a Greenfield Site: the Gap, Brisbane Box 6. Structuring policy dialogue on water reuse. The case of San Diego California Box 7. French decree authorizing rainwater harvesting for indoor non-potable uses

4 EXECUTIVE SUMMARY Populations in most OECD countries enjoy high levels of access to networked systems of water supply and sanitation. However, the maintenance of these systems is becoming more difficult because of the major investments required to repair and replace ageing infrastructure and the costs associated with meeting more stringent environmental requirements. It is expected that half of OECD countries will have to increase the level of expenditure on water infrastructure as percentage of GDP (OECD, 2007a). In addition, questions arise about the articulation of such services with water management issues. Water scarcity, the benefits of adjusting water quality to needs, the concern for making a better use of available resources, all argue that water supply services should be adaptable, resilient and flexible. In this context, the traditional economies of scale attached to piped water supply, single water use, and water-borne sewage treatment in centralized systems are being questioned. There are diseconomies of scale attached to large municipal systems for supplying water, in particular in megacities where high costs are attached to water transport and network maintenance, including work on roads to repair underground infrastructure. The strong technical path dependency of existing infrastructures generates rigidities which may be problematic in the context characterized above. Some governments and the private sector are examining alternative ways of providing water. In particular, reuse of (treated or not treated) grey or reclaimed water attracts a lot of attention, as it provides an alternative source of water. Reuse can be organised at different scales and, as noted by Yang and Abbaspour (2007), one key question from a policy perspective is to determine the optimal scale of wastewater reuse, from a technical, socio-economic, environmental and institutional perspective. Alternative water systems differ from prevailing ones in at least one of two dimensions: i) they reclaim and reuse water for a variety of uses; ii) they can be based on decentralized infrastructures, producing water where it is consumed. Markets for water reuse are booming. Experience with decentralized water accumulates in emerging economies and in rural areas; experience is more limited in OECD urban areas. Australia, Spain, some states in the US are pioneering these new technologies, spurred by serious constraints on water resources. There are debates about the pros and cons of alternative water systems, and about the contexts where they might be viable. This paper sheds some light on these debates, by reviewing the literature and available case studies. It identifies contexts where alternative water systems might be considered as an option for OECD governments and municipalities. It identifies a number of policy issues which have to be addressed before these systems can be deployed and contribute to tackling the challenges OECD countries face regarding water supply. This is a preliminary exploration and more work is needed to collect evidence and bring more light on these and related issues. 3

5 Pros and cons of alternative water systems Alternative systems have pros and cons. The discussion focuses on selected issues, namely: the investment and operating costs. Available data indicate that there is no absolute ranking of water systems based on costs. Regulation is one of the main drivers of costs for decentralised systems and for water reuse. Alternative systems may be cost effective, even in cases where central infrastructure is already in place; the capacity to internalize some externalities attached to improved water supply (e.g. capturing land and property value) and to harness new sources of private capital. Investment in decentralised water supply can be included in property development plans, thus taking some pressure off local public finance. From an environmental perspective, water reuse can reduce demand for fresh water resources, diversify water sources and enhance reliability of access to resource; it can reduce volume of wastewater discharged into the environment. Decentralized systems can reduce energy required to transport water from the point of production to the point of use; and reduce greenhouse gas emissions (due to energy savings). Alternative water systems have financial benefits as well: constructing fewer infrastructures and deferring and reducing costs for the construction of networks; relieving public finance from part of the financial pressure, as new players are incited to invest their own money in the (decentralized) infrastructure. Alternative systems are flexible and adaptable to changes in population and consumption, land use, and technologies. Alternative water systems have a number of drawbacks. They can generate additional costs, in particular when not integrated in the initial plans for service provision and building construction. From a revenue side, their financial attractiveness is limited by the fact that revenues do not reflect the positive externalities for the society at large (this is also true of conventional systems). Typically, revenue streams from non-potable reused water are limited and willingness to pay is low. This is so in part because the price of water does not reflect its full cost. These systems generate a number of risks, associated with public health and the economy of water services at the municipal level; for instance, they preclude cross subsidies and financial solidarity between rich and poor, especially if they are not operated in a coordinated way. Other concerns that apply to decentralized water systems are: how can decentralised systems constitute cohesive networks? What happens if the service provider goes bankrupt? How are tariffs set, revised, and approved? Who will undertake water quality testing at the customers taps? It follows that alternative systems can only be considered in particular contexts, and their most appropriate scale will depend on specific conditions. Where alternative water systems are viable Alternative water systems have been used in rural areas for decades. They obviously are an option in new urban areas where no central infrastructures pre-exist, and in extra-urban urban areas. In addition, alternative water systems might be considered in city centres with decaying water infrastructures or with infrastructures meeting diseconomies of scale or capacity constraints, and in projects of urban renewal. They are more competitive in unstable contexts, where flexibility, resilience 4

6 and adaptation are valuable (i.e. a context created by climate change in many places). They are even more relevant where property developers operate the buildings they invest in. In any case, the most appropriate infrastructure may very much depend on policy orientations, as no single system s performance is systematically superior for, e.g., water conservation, recycling nutrients, and keeping construction costs low. One size does not fit all the different functions of urban water services (e.g. supplying potable water, non-potable water uses, rain water management, sanitation) and the most appropriate scales for each function have to be combined and articulated. A combination of centrally-provided and alternative water systems is probably the most practical approach in many cases. Limited experience is available on the best ways to combine both approaches. More work is needed on the technical, regulatory, economic and financial aspects of this issue. Policy issues Alternative water systems fit in the variety of options OECD governments could consider, to address challenges associated with water supply, including in urban areas. However, they can only be deployed when water-related institutions and regulations are transformed into technology neutral enabling frameworks. Such frameworks would address the issues highlighted below. Public involvement, and transparency are critical when alternative ways of providing water are considered, because public acceptance is topical, especially in cases of water reuse for (direct or indirect) potable uses. There is a risk that responsibilities are blurred between municipalities (who generally are responsible for water provision), property owners (who may invest in decentralized systems), technology suppliers (who provide the equipment), and service providers (who operate and maintain these equipments). It follows that accountability and responsibilities have to be clearly defined. The regulatory framework has to be adjusted, to allow exploring the benefits of alternative water systems. While a variety of technical options exist to provide water, options in use are limited by planning regulation, norms for the quality of the product or service, standards for grey water reuse and for the techniques to be used. Recent initiatives at sub sovereign, national and supra national level indicate that regulatory frameworks can be reformed. In addition, water sector regulators need to be prepared to monitor water quality from a variety of different sources (e.g. fresh water abstraction, harvested rainwater and water treated) in multiple settings (in central plants, commercial and industrial buildings, and private houses). This requires capacity, financial and human resources. Setting the prices right for water is the first step towards stimulating markets for alternative water systems when they are needed. An increasing array of experience accumulates, from which governments, municipalities, the private sector, consumers and citizens at large can identify the best ways of combining existing infrastructure with alternative water systems. An informed policy dialogue on the available options, in a context that favours innovation and adaptation, is the best way forward. 5

7 INTRODUCTION Recent work by the OECD (OECD 2007 a, b) confirms that OECD countries face major challenges regarding the construction and the maintenance of water related infrastructure. It suggests that prevailing ways of providing water (essentially based on centralized infrastructure and single water use) may not be able to face these challenges. Alternative water systems may be part of the portfolio of options governments have to consider to achieve their water policy objectives. In this report, alternative water systems are defined by one or two of the following features: i) they recycle and reuse water for a variety of uses; ii) they can be based on decentralized infrastructures, producing water where it is consumed. Water reuse attracts a lot of attention. Markets are booming and a variety of technologies and systems are available to meet an increasing demand in OECD and emerging economies. The situation regarding decentralized ways of providing water is less clear: there are debates about the benefits and the costs of such options; there are questions about their relevance in an OECD context, especially in urban areas where centralized infrastructure is already in place. The objective of this report is to shed some light on the pros and cons of alternative water systems in OECD countries, in particular in urban areas. The paper identifies a number of policy issues which have to be considered before such options can effectively be considered and deployed in OECD urban areas. The paper has three chapters. The first one sets the scene. It recalls a number of challenges OECD countries face regarding water supply and sanitation and explains why prevailing ways of providing water may not be able to cope with them. Alternative water systems are described, and data is presented on their development. In the second chapter, the pros and cons of alternative water systems are assessed. The chapter builds on the available literature and on selected case studies in a variety of contexts. Some questions remain, as there is no comprehensive set of facts and data that systematically address all the facets of the issue. The last chapter identifies the main policy issues which have to be addressed to harness the full benefit of alternative water systems. In particular, governance regimes, regulatory frameworks and capacities have to be reformed, to adequately plan, design, construct, operate, and monitor such systems, should they be part of the portfolio of options governments implement in OECD countries. 6

8 OPPORTUNITIES FOR ALTERNATIVE WATER SYSTEMS The chapter explains why alternative water systems attract attention in the current context. Recent work confirms that OECD countries face daunting challenges as regards water supply and sanitation. It suggests that prevailing approaches, based on central infrastructure and single water use, may not be able to meet these challenges. In this context, alternative water systems are considered by a number of national and local authorities. They include water reuse and decentralized systems for water supply. Recent trends and data on related markets are compiled. Challenges that prevailing approaches face in OECD countries OECD countries face daunting challenges regarding water supply and sanitation, including in urban areas. It is unclear how prevailing approaches, based in single water uses and centralized, piped systems can cope with these challenges. These uncertainties stimulate research on alternative ways of providing water and sanitation. Alternative water systems are based on the so-called soft path, an approach which is not technology driven and suggests that a variety of ways of providing water and sanitation should be explored and/or combined. Current challenges related to water supply and sanitation in OECD countries According to Ashley and Cashman (2006), the key drivers likely to impact on the long-term demand for infrastructure in the water sector can be grouped under four broad headings: socioeconomic, technological, environmental and political. Socio-economic changes are expected to increase total and unit costs of water service infrastructure into the foreseeable future due to: population growth; population profile changes (e.g. ageing and more sophisticated life styles); demand for increased service quality; extended coverage and access to services; increasing share of the risks and functions (e.g. coping with rain water) associated with providing water services being borne by the private sector. Technological change is expected to attenuate the overall increasing costs of water services. This will be due to: new techniques (e.g. sensor and information and communication technology) and better ways of managing information and hence performance, resulting in smarter ways of operating new and current systems; greater energy and resource efficiency. Green infrastructure technologies (e.g. natural or engineered systems which use soils and vegetation to capture, cleanse and reduce storm water and other excess flows 1 ) and methods (e.g. integrated water resource management, payments for ecosystem services) can avoid additional infrastructures and treatments and save major costs (for 1 Common approaches include green roofs, trees and tree boxes, rain gardens, vegetated swales, pocket wetlands, infiltration planters, vegetated median strips, reforestation, and protection and enhancement of riparian buffers and floodplains. See the position of USEPA on this issue 7

9 instance, good management of watersheds draining into drinking water reservoirs can avoid artificial water filtration). Technological change also presents an opportunity to challenge some but not all of the ways in which water services are provided. The key question is: to what extent can technology bring about the closing of the water cycle such that the requirement to abstract new resources is minimised? This would require technologies that are reliable, cost effective, appropriate for those who must use them and capable of widespread adoption. Environmental/external stresses will be main change drivers. Shortages today very often result from rising abstraction levels and from mismanagement and unsustainable actions. But climate is likely to compound the problem of competition for water use. In Australia for example, droughts and water stress in the main cities have forced the adoption of a whole new range of approaches to managing water, based much more on the concepts of reuse, recovery and matching water quality to what the water is used for, and also to education of users (CSIRO, 2004). Such stresses can generate additional demand for security of access to resources. The degradation of watershed ecosystem services may result in shifts to engineered water filtration, thus increasing cost of water. Responses include new infrastructures and management techniques which build redundancy in the systems (to make sure that water will be supplied) and which ensure contaminant control to protect health and ecosystems. A report by Marsden Jacob Associates (2006) notes that differences in the way climate uncertainty and risk have been treated correlate with recent levels of expenditure on water supply infrastructure: the city of Perth has incorporated an unfavourable scenario on climate into planning, for many years; over the past five years, per capita expenditure in Perth, has been twice or more the level of water supply investment in Sydney, Melbourne, Brisbane and Adelaide, which have not adopted scenario planning approaches or have only done so very recently. Political changes are expected to increase the relative costs of future water service delivery, principally due to: land use and urbanisation control processes; effectiveness of governance up and down the process, at national and/or local levels; the forms and needs of revenue collection (which may not improve due to political will); increasing service levels driving infrastructure performance up; for instance, in Europe, the lowering of lead content from 50 to 10 g/l (as required by the EU Drinking Water Directive adopted in 1999) will cost up to 35 billion $ while, according to Barraqué (2003), there is no evidence that the former level provokes lead poisoning. Projections illustrate the scale of the challenges that face those responsible for planning and providing for water service needs (see OECD 2007a): most OECD countries will have to increase the share of their GDP allocated to the water and sanitation sector over the next twenty years. This can be illustrated by a number of instances. Coverage is not comprehensive: in Europe, more than 20 million people lack safe sanitary facilities. When the infrastructure exists, it can be too old and ill-adapted to the current challenges: London s sewerage collector system overflows in case of heavy rains and pours into the Thames. The existing infrastructure can also create environmental problems (e.g. Baltic sea pollution from wastewater). Although the benefits of investments are likely to outweigh the costs, it does not follow that the projected expenditures will be realised. Indeed, over the last two decades, investment rate has been falling in water, in most OECD countries (OECD, forthcoming). The evolution of capital stock in the water sector relative of GDP tends to decline in countries with higher levels of provision (Austria, the Netherlands, or the U.S.). 8

10 Limitations of prevailing approaches to water supply In OECD countries, prevailing ways of providing water and sanitation are based on piped water supply and water-borne sewage treatment in centralized systems using a series of accepted technologies. It is not clear how these approaches will be able to adjust to the challenges identified above. Indeed, some observers claim that we have invested a lot of money in building infrastructure, but we have not developed sustainable infrastructures through this investment (Michael Deane, Associate Assistant Administrator for Water, USEPA). In Rees et al. s words, the 1980s Water Decade provides lessons for the future: plenty of infrastructure was created but, in many cases, it was badly chosen, poorly maintained, and lacked supporting institutions. Consequently, the investments did not realise the expected benefits and did not adequately address the service deficit (Rees et al., 2008). The city of Mexico illustrates this observation. According to Tortajada and Castelan (2003), Construction of infrastructural projects ad infinitum to bring more and more water to the metropolitan area is neither sustainable, nor economically feasible, nor is it environmentally and socially desirable. With the existing poor-management practices, investment costs would skyrocket to transport more and more water from increasingly distant and expensive sources, higher operating costs would be incurred for energy, land subsidence will accelerate due to increasing groundwater withdrawals, the quality of groundwater abstracted will decline, higher subsidies and higher investments would be necessary to cover operation and maintenance costs, etc. This represents a never ending vicious circle. The quality of life is likely to improve for the rich, but continue to worsen for the poor. Because there are negative externalities and diseconomies attached to large-scale, centralized infrastructure, the soft path for water emphasizes improving the productivity of water use rather than seeking endless sources of new supply. It delivers water services and qualities matched to users needs, rather than just delivering quantities of water. It applies economic tools such as markets and pricing, but with the goal of encouraging efficient use, equitable distribution of the resource, and sustainable system operation over time. It includes local communities in decisions about water management, allocation, and use. The soft path opens new avenues for accessing capital. The soft path explores four opportunities (Gleick et al., quoted in OECD, 2007b). The first opportunity is changes of scale. Planning water supply and sanitation at alternative scales can increase cost-effectiveness of water services, increase revenues, and introduce new models to meet capital needs. On the one hand, regionalization of water services has improved efficiency, cost-effectiveness and watershed management in key areas in France, Canada, Portugal, and the United States. Expanding the scope of service can improve a water system s ability to finance needed investments. On the other hand, decentralized systems are changing who is responsible and paying for water infrastructure. Engineering firms are building water systems using private capital, and maintaining ongoing service contracts to finance this capital. And home and land owners are investing their own capital (or servicing the debt on needed capital) in order to build onsite systems for singlefamily or multi-family complexes. It is important to acknowledge that water and sanitation services cover a range of services which can be organised at different scales: potable water supply, supply of water for non potable uses, rain water harvesting and flood mitigation, wastewater collection, treatment, etc. The second opportunity to meet infrastructure needs is through demand management. Demand management changes the nature of needs for infrastructure. Increasing water productivity and efficiency, and improving conservation can reduce the need for new and expensive water supply or 9

11 wastewater treatment projects. As new water supply projects become more expensive to source water from further distances, the cheapest new source of water has often been water gained through conservation, efficiency, and improved management. Many OECD countries have successfully reduced water use per capita and in total in recent years - indicating that the right policies, along which pricing plays a prominent part, can lead to a decoupling of water use from economic and population growth. This was reflected in the OECD Horizontal Programme on Water which has investigated how pricing strategies can address policy questions related to water supply and sanitation (OECD, 2009). Competition is a key opportunity to reduce ongoing financing needs and improve the capacity of utilities to access financing. Competition that increases efficiency and improves water system management will reduce costs and can also have a significant impact on the utility s credit worthiness, thus providing access to (cheaper) private capital and public bonds. However, competition and decentralisation require a strong capacity on the part of governments and regulators to monitor water abstraction, service quality and management practices. The capacities needed by governments to monitor and manage a variety of private actors are analysed in a distinct section of the OECD Horizontal Programme on Water. The fourth opportunity is public involvement. In the end, the public, whether as ratepayers, taxpayers, or stockholders, will finance whatever debt is incurred to build new infrastructure. Ultimately, water utilities must convince ratepayers, taxpayers, and/or stockholders of the need for new infrastructure investments and the utility s ability to manage those infrastructure improvements effectively. Public involvement can facilitate larger investments in the water sector, or help identify the need and opportunities for smaller investments. It is a requisite to improve demand management and to encourage efficient use and equitable distribution of the resource. This again has been considered in the OECD Horizontal Programme on Water which has explored how policy dialogues can support the design of sustainable financing strategies for water-related investment. Trends in the provision of water supply This section proposes a classification of ways for supplying water. It reports on experiences based on alternative water systems, and monitors trends in the development of related markets. Alternative ways of supplying water Ways of supplying water can be characterized along two axes. One deals with the infrastructure, which can be centralized or decentralized. The other deals with the water which is used: either freshwater only, for a single use; or alternative sources of water. Alternative sources of water include: rainwater, which can be harvested and treated locally; grey water, i.e. non-industrial wastewater generated from domestic processes; USEPA defines grey water as non-drinkable water that can be reused for irrigation, flushing toilets, and other purposes; grey water can be used immediately or treated and stored; it is distinct from black water, which contains more polluting chemical and biological contaminants; and reclaimed water, i.e. former wastewater that has been treated to remove solids and certain impurities. It is only intended to be used for non potable uses (e.g. irrigation, dust control, fire suppression); with more advanced treatment, it can be used for indirect potable reuse (i.e. discharged into a water body before being used in the potable water system). 10

12 Table 1. A typology of ways of supplying water Central infrastructure Decentralized infrastructure Freshwater only Prevailing in OECD countries Single quality water is provided by central infrastructures. Waterborne sewerage is centrally collected and treated in a plant usually located at the outskirt of the urban area Not common in OECD urban areas Relies on point of use resources (wells). Connections to central infrastructure may be needed to ensure reliable sourcing Alternative sources of water In use in some contexts Treated or untreated rain and grey water is sent back to the city where it is used again. The system requires an additional network and energy is used to transport wastewater and reclaimed water Widespread in specific contexts Water is produced and treated locally (on the point of use). Treated or untreated rain and grey water is used for (usually non potable) uses Central versus decentralized infrastructure Water can be supplied by decentralised systems. This is the case when the source of water is local (wells). This is also the case when water is treated locally: rain water can be harvested at any scale. This is also the case when grey water is collected, treated and used locally. Similarly, reclaimed water can be used where it has been treated. Decentralised systems for wastewater reclamation are increasingly in use in collective buildings (hotels, hospitals, schools) or industrial facilities. In Japan, in 2003, more than 1,000 on-site individual buildings and block-wide wastewater recycling systems generated water for non-potable urban applications (toilet flushing in commercial buildings and apartment complexes) (Funamizu et al., 2008). Centralized and decentralized approaches do not need to be exclusive. First, it is more appropriate to speak of degrees of de/centralization. Second, communities can combine both approaches. Freshwater versus alternative sources of water As defined above, alternative sources of water include rain and storm water, grey and reclaimed water. Treatment of alternative sources of water is adjusted to the quality standards of different applications. There are two broad categories of applications: potable and non potable ones. Non potable uses include irrigation (for crops, parks and golf courses), some industrial applications, some uses for households, including outdoor uses (such as gardening) and indoor applications (e.g. flushing toilets or washing machines). Alternative sources of water can be used for direct or indirect potable reuse (water is discharged into a water body before being used in the potable water system). The California Local Government Commission makes a distinction between reuse and recycling (see Reuse involves using untreated, uncontaminated wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines and laundry tubs a second time around, for an appropriate purpose. Recycling means the use of treated wastewater for appropriate purposes. Rainwater harvesting requires that tanks be installed, in existing or new homes, to collect the runoff from the roof area; these tanks would be connected to indoor end uses (such as toilet flushing 11

13 and washing machines) and outdoor (watering the garden). Wastewater reuse requires retrofitting systems in houses so that grey water from the house can be collected, treated and reused (for the same end uses). In the case of new homes, grey water systems can be integrated in the initial planning, saving investment costs. Reuse can be combined with either central or decentralized infrastructure. This report discusses the pros and cons of harnessing alternative sources of water (rainwater, grey water, reclaimed water) and of the systems which are required to do this in an efficient and cost effective way (onsite systems to harvest and treat rainwater; decentralized systems to collect, treat and reuse grey water, or to reclaim wastewater). The focus is on urban areas in OECD countries. While a lot of experience has been gained on water reuse (see below), it is less clear how decentralized systems can adjust to OECD urban areas, which are already equipped with centralized infrastructures. Sharing experiences that work and their limitations An increasing number of applications illustrate how alternative water systems can be implemented in urban areas in developed economies. They indicate that alternative water systems are not limited to rural areas (where land is abundant and density is low) and to developing countries (where infrastructures have to be built or extended). In old Europe, where cities are equipped with central infrastructure to supply water and to collect and treat wastewater, experiments with alternative water systems are burgeoning. ARENE (2005) reports on a number of them which share common water-related features: i) rainwater is harvested in tanks (in-house or underground) and used for flushing toilets, washing machines and gardens; ii) run offs are collected and treated so as to replenish aquifers; iii) some experiments reuse water for indoor or outdoor non potable applications: In BedZED (UK), renewable sources of water (rainwater, reclaimed water) supply 18% of the daily consumption of water. Wastewater is treated in a Living Machine (Green Water Treatment Plant): water is treated biologically and through ultraviolet light to a level that complies with requirements for toilet flushing and gardens. In Vauban-Fribourg (Germany) rainwater is harvested and used for toilet flushing, washing machines and gardens; in a pilot building, grey water is collected, treated and reused (for indoor and outdoor non potable applications); biogas is produced out of wastewater, which feeds gas appliances in the homes. In Hammarby Sjörstad-Stockholm (Sweden), the initial target was to reduce water consumption by 50%, by a variety of techniques, including reclaiming wastewater and installing filters in all taps that mix air into the water; the target to 2015 is even more ambitious. Singapore has developed one of the world s most advanced water reuse programmes. The reuse programme, called NEWater, relies on advanced microfiltration, reverse osmosis and ultraviolet exposure to clean and treat wastewater for potable consumption. NEWater has been recognized as an international model for innovation in water management, most recently winning the Environmental Contribution of the Year award from the London-based group Global Water Intelligence. Namibia s capital city, Windhoek, is the only supported instance of reclaimed wastewater used for direct potable use; one third of the population (250,000 people) are served this way. 12

14 In China, a number of developments treat water at the level of a house, or of a commercial building. In Beijing, it is required that newly developed residential buildings with construction area over 30,000 m2 build on-site wastewater reuse facilities (Yang, Abbaspour, 2007). The 2008 Olympic Games have been an opportunity to demonstrate savoir-faire in this area (see Box 1). Box 1. Water Reuse at the Olympics: Beijing Bei Xiao He Beijing BeiXiaoHe water treatment plant is located at the North of Beijing, China. It is responsible for the water supply of the Olympic Park. Water reuse is part of a solution where potable water is conserved, wastewater discharge is reduced, and a reliable and verifiable quality of water is ensured. According to the CSR Newswire, the sewage water reuse facility in BeiXiaoHe Wastewater Treatment Plant constitutes one of the world s argest membrane bioreactor plants; it is designed to produce 15,000 m(3)/day of filtered water for landscape care. The Reclaimed Water Reuse for Beijing Capital International Airport, with capacity of 10,000 m(3)/day, will recycle municipal wastewater for the daily water consumptions of the airport and to help meet the needs of approximately 20,000 visitors per day. The treated water from the Reclaimed Water Reuse for Beijing Economic- Technological Development Area (BDA), with capacity of 20,000 m(3)/day, will be supplied as industrial water to the companies in BDA. Combined, these three facilities will provide 45,000 m(3)/day of water. Source : CSR Newswire and others In Hong Kong, the Total Water Management aims at meeting long-term water needs, while supporting future population and economic growth. It integrates reclamation (defined as lower quality water used to replace high quality water for non-potable purposes), new sources of water, water conservation and demand management (see Box 2). Alternative ways have been systematically assessed and a number of pilot projects are under way. The issue of public acceptance is explicitly being addressed. 13

15 Box 2. Water reclamation, Hong Kong The Government has conducted pilot schemes in Ngong Ping and Shek Wu Hui. These schemes, commissioned in 2006, use reclaimed water for toilet flushing and gardening. Both pilot schemes were expected to be completed by the end of They are being monitored in respect of operating conditions, reclaimed water quality and public acceptance of using reclaimed water. The interim results of surveys on public acceptance to the use of reclaimed water under the two pilot schemes are favourable. Subject to the final results of the two pilot schemes, reclaimed water from Shek Wu Hui Sewage Treatment Works could be provided to consumers in Sheung Shui / Fanling for toilet flushing and other non-potable uses. These schemes take place in a wider review of options, which also cover rain water harvesting and grey water reuse: demonstration projects are considered to create markets (see chapter 3). The review also covered expansion of water gathering grounds and reservoir storage and desalination. The review concluded that expanding water gathering grounds and reservoir storage is of very low priority for Hong Kong. Seawater desalination by reverse osmosis can yield the largest quantity of new water supply in Hong Kong. The pilot tests were completed in 2007 and confirmed that this technology is viable for Hong Kong. Source: ACQWS (2008), Total Water Management Strategy in Hong Kong, Paper No. 20 ( The global market for water reuse Water is already reused in a number of OECD and developed countries. According to a survey by Jimenez and Asano (2008), water is primarily reused for irrigation in Southern Europe, the US and Canada; this includes landscape and golf course irrigation. Industrial uses are prevalent in Northern Europe and Asia. Municipal reuse of water also exists in Asia (e.g. Korea, Singapore), for activities requiring low quality water. The markets for reused water are potentially large. According to market insights from Global Water Intelligence (see GWI, 2005), half of the world s major industrial companies and one quarter of major cities will consider water reuse in the decade from 2005 to While desalination is a bigger market, reuse is expected to grow at a faster pace. The overall water reuse capacity is projected to rise from 19.4 million m3/d in 2005 to 54.4 million m3/d in GWI notes that a large proportion of this capacity will involve secondary water treatment only, thus not complying with standards for potable water. Siemens anticipates that desalination and reuse markets will grow together from 48 million m 3 /d in 2006 to 158 million in 2016 (see Siemens, 2008). In the OECD area, Japan, Australia, the US (California, Florida) already have experience in using reclaimed water, in particular in regions living under water stress. In these regions, reclaimed water has been used for a number of purposes, including groundwater recharge programmes. Western Europe has not fully used this alternative resource yet, although the potential is high in regions where water in scarce (Spain), or where water resources are overexploited (Belgium, the Netherlands, parts of Germany and the UK; see OECD, 2008). Spain has a plan to triple the volume of wastewater reuse by 2015; up to 1.5 km 3 of wastewater could be reused annually within the next few years. Among non OECD countries, China will be a major market, with the development of wastewater treatment capacity and water shortages in the North East. Market prospects in the Middle East and South Asia depend on the extension of wastewater collection and treatment infrastructure. 14

16 GWI identifies five market drivers for water reuse: increased demand for water; reduced availability of water supply; affordability due to falling costs for membrane technologies; practicality of water reuse as a local solution; public policy (for instance, stringent standards for wastewater discharge in Europe are an incentive to recycle water). The most promising trends for wastewater reuse are (municipal) irrigation or industrial use. In a number of projects (completed or ongoing), treated wastewater is stored in aquifers. The figures below show how reclaimed water is used in California (source: Agricultural Irrigation: 46% Landscape Irrigation: 21% Groundwater Recharge: 14% All Other Uses: 19% One application of reclaimed water is dual reticulation systems in new build residential areas providing separate pipes for potable and non-potable water. Here comes a dilemma: either treat reclaimed water so that it is potable, or build secondary networks. 15

17 PROS AND CONS OF ALTERNATIVE WATER SYSTEMS This chapter presents available information on the pros and cons of alternative water systems, compared to centralized services. It builds on the general literature and on available case studies. The discussion focuses on selected issues: 1. the investment and operating costs. Scarce data indicate that there is no absolute ranking of water systems based on costs. Regulation is one of the main drivers of costs for decentralised systems and for water reuse. Alternative water systems may be cost effective, even in cases where central infrastructure is already in place; 2. the capacity to internalize some externalities attached to improved water supply (e.g. capturing land and property value) and to harness new sources of private capital. These considerations point at the contexts where alternative ways of supplying water can be viable. Such contexts include, but are not limited to, rural areas (not covered in this report), new urban areas where no central infrastructures pre-exist; extra-urban, or low-impact urban areas. Additional contexts where alternative water systems might be considered include instances of urban renewal, and city centres with decaying water infrastructures or with infrastructures meeting diseconomies of scale or capacity constraints. Moreover, alternative water systems could be more competitive in unstable contexts, where flexibility and adaptation are valuable. They are even more relevant where property developers operate the buildings they invest in. In any case, the most appropriate infrastructure will depend on policy orientations, as no single system performs best for water conservation, recycling nutrients, and keeping construction costs low at the same time. A combination of central and alternative water systems may be an answer. Cost factors for water reuse and decentralized systems This section identifies some costs drivers for water reuse and for decentralized systems, taking account of both investment and operation and maintenance costs. It indicates that alternative water systems can be cost effective in certain situations, especially when central infrastructures meet diseconomies of scale or capacity constraints. It indicates that the length of the payback period is essentially regulation-driven. It presents a case study where central systems and alternative ways have been systematically assessed. The section can only scratch the surface as systematic analyses based on public, comparable information are lacking. 16

18 Assessing the cost effectiveness of alternative water systems Marsden Jacob Associates (2006) analyses the costs of major supply and demand options available to Australian cities. The conclusions emphasise that, all things being equal, contextual features determine the cost advantage of any option: most options have very low cost in favourable locations and situations; many options have very high cost (>$3.00/kl) in unfavourable locations and situations; the costs of pipelines and pumping have a dominating influence where water needs to be transported over distance. It follows that there is no simple universal cost ranking which can be simply applied to each and every situation. However, in most cases, there is some advantage at cutting the costs related to pipelines and pumping to transport water over long distance. This explains why urban services are meeting diseconomies of scale when the last urbanites are finally connected (Barraqué, 2003); similarly, wastewater reclamation will be more cost effective when treatment facilities are located close to potential users, be they industrial, agricultural, or municipal. As noted by the Rocky Mountain Institute, if decentralized systems lose the advantages of economies of scale that are possible in capital and operation and maintenance costs, they also avoid diseconomies of scale that are inherent in centralised water systems. In the case of wastewater collection and treatment: Given that collection system costs can be 80 percent or more of total systems costs, collection diseconomies of scale can overwhelm treatment economies of scale, resulting in decentralized systems being the more economical choice (Rocky Mountain Institute, 2004). The dominating influence of transport costs also explains why reuse is more expensive when water is treated at a central location (typically a central wastewater treatment plant away from the city) and reclaimed water is transported back into secondary networks and plumbing in the buildings where it will be used. According to Marsden Jacob Associates (2006), major new water reuse initiatives are frequently comparable with, or more expensive than, desalination due to long transportation distances and/or the need for third pipe systems. This is where decentralised systems have an advantage, saving on (investment and operation and maintenance) transport costs for both wastewater and reclaimed water, using less infrastructure. Other factors have to be accounted for, when assessing the cost effectiveness of alternative water systems. The Rocky Mountain Institute (2004) has systematically compared the costs and benefits of decentralized wastewater treatment, relative to centralized systems. As regards financial planning and financial risk, the Institute notes that the small unit size of decentralized system allows closer matching of capacity to actual growth in demand. Decentralized capacity can be built house-by-house, or cluster-by-cluster, in a just in time fashion. This provides a number of important benefits. It moves capital costs of capacity to the future. The result is often a more economical approach than building centralized treatment capacity or extending sewers (depending on many other factors). Spreading out capital costs also typically means that a community needs to incur less debt, compared to the borrowing requirements of a large up-front capital investment in capacity. This can reduce the financing costs for the community. [ ] Some potential financial disadvantages of decentralized systems are that the large number of systems can increase design, permitting, financial, and other transaction costs of a wastewater service strategy. Also, lenders may perceive individual and small wastewater system debt as riskier 17

19 investments compared to municipal borrowing, so the unit costs of debt may be higher. Decentralization also concentrates the financial risks of individual system failures on individuals or clusters of residents, in contrast to the insurance-like spreading of risks of failure across large numbers of users that centralized systems can provide (Rocky Mountain Institute, 2004). It remains to be seen whether similar arguments apply to decentralised water supply. Regulatory drivers of the payback period for alternative water systems Regulation drives investment and operation and maintenance costs of alternative water systems. All over the world, reclaimed water must be channelled through separate infrastructure and plumbing, which adds to investment costs. In France, an estimate for such up-front investment is around 20 k for a public building. This can be considered as marginal compared to the overall construction costs. This is less so for private houses. Reuse systems bear specific operation costs, such as the maintenance of the system, the coloration of non-potable reused water (depending on regulation) and the monitoring of water quality. On the other hand, they allow to buying less water from the central service and to discharge less wastewater into the main sewer or the environment. Savings in operation and maintenance can compensate the initial up-front investment, when the party who pays for the investment operates the building/house 2. When the investor operates the building, the main financial criterion to compare central and decentralized systems will be the payback period: how many years does it take for the savings on operation and maintenance to compensate for the initial higher up-front costs? Michel Le Sommer (personal communication) indicates that, in the case of France, where the average price of water is roughly 3 per m3, the payback period of such systems is between 15 and 20 years. Regulation is a major driver of the payback period. The payback period depends essentially on the standards set by the regulatory agencies, environment and/or health authorities, for reused water (what water can be harvested, quality standards of reused water for specific applications, building standards, etc.). It also depends on how water supplied by the central system is priced (are investment and operation and maintenance costs fully recovered?) and how the environmental externality of discharging (treated) water to the environment is reflected into taxes/levies for wastewater discharge. The Rocky Mountain Institute notes that high effluent standards tend to favor centralization, although it is possible to produce high quality effluent with some decentralized technologies. Some of these technologies, such as small-scale constructed treatment wetlands, may be more land-intensive (Rocky Mountain Institute, 2004). Sustainability of water reuse in two German cities 3 Hiessl (2005) has systematically assessed and compared the costs of providing water to two German cities using either central or alternative water systems. 2 Note that this is not always the case. There are cases of split incentives, i.e. when the landlord bears the costs related to investment in water efficiency, while the benefits accrue to the tenant. Split incentives are common in energy efficiency, and lessons can be learned from experience of policies to address them (e.g. UK s Landlord s Energy Saving Allowance). 3 This section is adapted from Hiessl et al.,

20 Three scenarios were developed, for two German cities, with a long-term perspective up to 2050: "Continuation", "Municipal Water Reuse", and "Local Recycling". Technological, organizational, and institutional innovations were integrated into coherent urban water systems with improved ecoefficiency with respect to water, nutrients, and water polluting materials. In the "Continuation" scenario, water and sanitation are provided through central infrastructure. Major improvements in eco-efficiency accrue from a more systematic separation of rainfall runoff and wastewater and through innovative technologies such as membrane technology for wastewater treatment. The "Municipal Water Reuse" scenario takes a decentralized approach for rainwater management and introduces a closed loop system to provide non-potable water uses in industry, households, and municipal purposes. The "Local Recycling" scenario abandons the central water supply and wastewater systems altogether and uses completely decentralized systems to provide potable water from rainwater and water for non-potable uses through reclaiming various grades of wastewater. The scenarios are assessed and evaluated with respect to their sustainability, defined along a set of 44 criteria, grouped into economic, social, and ecological dimensions. Preliminary results indicate that the "Local Recycling" scenario prevails with regard to most of the criteria. However, the other scenarios succeed in various single criteria. The "Municipal Water Reuse" scenario, for example, has advantages in terms of water conservation, reduction of discharge of treated wastewater to receiving water bodies, recycling nutrients, and the energy production. The "Continuation" scenario is advantageous with respect of acceptance and construction expense. Harnessing new sources of finance: capturing some of the rent attached to water services Peterson (2006) notes that urban land values are created in part by public investment and other services made possible by municipal investment. It is economically appropriate therefore for municipalities to capture part of the land-value increment they create through their investment. Land value capture as a means to finance municipal infrastructure More attention has been brought to bear recently on the potential of land value tax, whereby a proportion of the increased value that accrues to landowners benefiting from new or improved infrastructure in the proximity is captured and used to fund the infrastructure provided. Successfully conceived and implemented, it shows interesting possibilities for integrated financial, land-use and infrastructure planning. In Shanghai, landowners and property developers already contribute to waterrelated investment. Half of financing for fixed assets over the period came from self-raised funds, i.e. financial resources raised by public developers in urban development projects. The rent that these institutions create in developing industrial, commercial or housing zones is invested back into financing infrastructures, including water and sanitation (Lorrain, 2008). Where infrastructures are being put in place in already densely populated, built-up areas, land value capture is limited. But where relatively undeveloped areas benefit from new infrastructures, it has considerably more potential. An interesting recent illustration, although not in the water sector, is the Copenhagen metro in Denmark (see Box 3). Building on experience in China, Hong Kong, Ethiopia and the US, Peterson (2006) notes that, under specific conditions, exchanging landholding for infrastructures can contribute to infrastructure financing. Now, land leasing can only be a transitional infrastructure-financing strategy: at some point in time, the supply of land available for lease or sale will run out and cities will have to rely more on revenues from services provided by the infrastructures to recover capital costs. Moreover, such 19